By WILLIAM A. HAMMOND, M.D., Surgeon-General, U.S. Army (Retired List); Professor of Diseases of the Mind and Nervous System in the New York Post-Graduate Medical School and Hospital.

In a very interesting account of a journey from the Pacific Ocean through Asia to the United States, by Lieutenant B.H. Buckingham and Ensigns George C. Foulk and Walter McLean,2 United States navy, I find an affection of the nervous system described which, on account of its remarkable characteristics, as well as by reason of certain known analogies, I think should be brought to the special notice of the medical profession. I quote from the work referred to, the following account of this disease. The party is on the Ussuri River not far from its junction with the Amur in Eastern Siberia: "While we were walking on the bank here we observed our messmate, the captain of the general staff (of the Russian army), approach the steward of the boat suddenly, and, without any apparent reason or remark, clap his hands before his face; instantly the steward clapped his hands in the same manner, put on an angry look, and passed on. The incident was somewhat curious, as it involved a degree of familiarity with the steward hardly to have been expected. After this we observed a number of queer performances of the steward, and finally comprehended the situation.

It seemed that he was afflicted with a peculiar mental or nervous disease, which forced him to imitate everything suddenly presented to his senses. Thus, when the captain slapped the paddle-box suddenly in the presence of the steward, the latter instantly gave it a similar thump; or, if any noise were made suddenly, he seemed compelled against his will to imitate it instantly, and with remarkable accuracy. To annoy him, some of the passengers imitated pigs grunting, or called out absurd names; others clapped their hands and shouted, jumped, or threw their hats on the deck suddenly, and the poor steward, suddenly startled, would echo them all precisely, and sometimes several consecutively. Frequently he would expostulate, begging people not to startle him, and again would grow furiously angry, but even in the midst of his passion he would helplessly imitate some ridiculous shout or motion directed at him by his pitiless tormenters. Frequently he shut himself up in his pantry, which was without windows, and locked the door, but even there he could be heard answering the grunts, shouts, or pounds on the bulkhead outside. He was a man of middle age, fair physique, rather intelligent in facial expression, and without the slightest indication in appearance of his disability.

As we descended the bank to go on board the steamer, some one gave a loud shout and threw his cap on the ground; looking about for the steward, for the shout was evidently made for his benefit, we saw him violently throw his cap, with a shout, into a chicken-coop, into which he was about to put the result of his foraging expedition among the houses of the stanitza.

"We afterward witnessed an incident which illustrated the extent of his disability. The captain of the steamer, running up to him, suddenly clapping his hands at the same time, accidentally slipped and fell hard on the deck; without having been touched by the captain, the steward instantly clapped his bands and shouted, and then, in powerless imitation, he too fell as hard and almost precisely in the same manner and position as the captain. In speaking of the steward's disorder, the captain of the general staff stated that it was not uncommon in Siberia; that he had seen a number of cases of it, and that it was commonest about Yakutsk, where the winter cold is extreme. Both sexes were subject to it, but men much less than women. It was known to Russians by the name of 'miryachit'".

So far as I am aware - and I have looked carefully through several books of travel in Siberia - no account of this curious disease has been hitherto published.

The description given by the naval officers at once, however, brings to mind the remarks made by the late Dr. George M. Beard, before the meeting of the American Neurological Association in 1880, relative to the "Jumpers" or "Jumping Frenchmen" of Maine and northern New Hampshire.3

In June, 1880, Dr. Beard visited Moosehead Lake, found the "Jumpers," and experimented with them. He ascertained that whatever order was given them was at once obeyed. Thus, one of the jumpers who was sitting in a chair with a knife in his hand was told to throw it, and he threw it quickly, so that it stuck in a beam opposite; at the same time he repeated the order to throw it with a cry of alarm not unlike that of hysteria or epilepsy. He also threw away his pipe, which he was filling with tobacco, when he was slapped upon the shoulder. Two jumpers standing near each other were told to strike, and they struck each other very forcibly. One jumper, when standing by a window, was suddenly commanded by a person on the other side of the window to jump, and he jumped up half a foot from the floor, repeating the order. When the commands are uttered in a quick, loud voice, the jumper repeats the order. When told to strike he strikes, when told to throw he throws whatever he may happen to have in his hand.

Dr. Beard tried this power of repetition with the first part of the first line of Virgil's "aeneid" and the first part of the first line of Homer's "Iliad," and out-of-the-way words of the English language with which the jumper could not be familiar, and he repeated or echoed the sound of the word as it came to him in a quick, sharp voice, at the same time he jumped, or struck, or threw, or raised his shoulders, or made some other violent muscular motion. They could not help repeating the word or sound that came from the person that ordered them, any more than they could help striking, dropping, throwing, jumping, or starting; all of these phenomena were indeed but parts of the general condition known as jumping. It was not necessary that the sound should come from a human being; any sudden or unexpected noise, as the explosion of a gun or pistol, the falling of a window, or the slamming of a door - provided it was unexpected and loud enough - would cause these jumpers to exhibit some one or all of these phenomena. One of these jumpers came very near cutting his throat, while shaving, on hearing a door slam. They had been known to strike their fists against a red-hot stove, to jump into the fire and into water. They could not help striking their best friend if near them when ordered.